sbin/hammer/cycle.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sbin/hammer/cycle.c,v 1.1 2008/05/11 20:44:44 dillon Exp $
  35  */
  36
  37 #include "hammer.h"
  38
  39 int64_t
  40 hammer_get_cycle(int64_t default_obj_id)
  41 {
  42         int64_t obj_id;
  43         FILE *fp;
  44
  45         if ((fp = fopen(CyclePath, "r")) != NULL) {
  46                 if (fscanf(fp, "%llx\n", &obj_id) != 1) {
  47                         obj_id = default_obj_id;
  48                         fprintf(stderr, "Warning: malformed obj_id in %s\n",
  49                                 CyclePath);
  50                 }
  51                 fclose(fp);
  52         } else {
  53                 obj_id = default_obj_id;
  54         }
  55         return(obj_id);
  56 }
  57
  58 void
  59 hammer_set_cycle(int64_t obj_id)
  60 {
  61         FILE *fp;
  62
  63         if ((fp = fopen(CyclePath, "w")) != NULL) {
  64                 fprintf(fp, "%016llx\n", obj_id);
  65                 fclose(fp);
  66         } else {
  67                 fprintf(stderr, "Warning: Unable to write to %s: %s\n",
  68                         CyclePath, strerror(errno));
  69         }
  70 }
  71
  72 void
  73 hammer_reset_cycle(void)
  74 {
  75         remove(CyclePath);
  76 }
  77